Most tourists come to Castle Island to have a picnic, enjoy the views and stroll along Harborwalk, which covers almost half of the island before clubbing with Head Island Causeway down at the island's base tip. The Causeway circles around Pleasure Bay itself. At the top, historic Fort Independence overlooks the Boston Harbor Islands, offering gorgeous views and usually a cool wind. At the highest point of Castle Island stands Fort Independence, a massive 5-pointed dim rock structure worked somewhere in the range of 1834 and 1851. Fortress Independence forestalled British maritime attacks during the War of 1812 because of its strategic area. You can join 1-hour free tours of Fort Independence on most Saturdays and Sundays, and explore on top of the fortification without a local area specialist for city skyline nightfall viewings on most Thursday evenings throughout the summer. Challenge your youngster to a slope race. The various hills around the Fort are ideal for moving contests! The Fort is open in evenings from 7pm on Thursday until Dusk in August for Twilight Skyline Viewing. This is the solitary time guests are permitted to stroll on the upper level of the Fort.